The invention relates to a peristaltic pump comprising a pump tube with elastically deformable wall, which pump tube is arranged in a pump housing at the bottom thereof and is fitted into the pump housing, substantially in a U,shape in plan view between two connection ends - with a portion which is curved in a part-circular configuration around a shaft of a rotor within the wall of the peristaltic pump and at a redial spacing thereto, the cross-section of the pump tube being partially varied during the conveying operation by at least one member of the rotor, which presses the pump tube in respect of cross-section against a support means, with a reduction in the internal vole.
A peristaltic pump of that kind is described in British patent specification No 628 785, having a pump tube and pressure rollers which produce in the interior of the tube a chamber portion which is closed off by two squeeze locations. When the rotor rotates the pressure rollers, as squeezing members, roll against the stationary pump tube which bears against the wall of the housing, and the squeeze locations are displaced with the pressure rollers in the conveying direction, whereby the material to be conveyed, which is in the interior of the tube, is conveyed from the tube intake to the discharge end of the pump tube. The squeeze location which is adjacent the pump intake, by virtue of the return force of the tube wall, produces a suction force on material to be conveyed which is disposed in an upstream-position supply container and which is thus drawn in and then transported by the above-described chamber portion to the discharge end of the pump tube.
In order to be able to influence the contact pressure characteristics as between the pump tube and the pressure roller, the roller spindles are displaceable on a support structure, with the result that inaccurate settings occur in particular when untrained personnel work on the tube pump.
In the state of the art irregular pressures on the pump tube are inevitable, and as a result adverse influences on the service life of the pump tube due to non-parallel deformation of the pump housing and the rotor, caused by one-sided transmission of force from the wall of the pump housing into the bottom of the housing and central transmission of force from the rotor rim by way of spokes to the rotor hub.
In quite general terms, in known peristaltic pumps, a large detrimental space, a space filled with lubricant/coolant or in the event of rupture of the tube with fluid being conveyed of uniform depth over the entire pump housing cross-section is found to be disadvantageous. Lubrication and cooling of the squeezing member of the slide shoe and the pump tube by dipping and spraying could not provide any remedy in that respect.
Those deficiencies are of significance not least also for the reason that on the one hand, in particular when dealing with dirty or corrosive agents to be conveyed, bursting or rupture of the pump tube can result in extremely undesirable contamination of the area around the pump while on the other hand replacing the pump tube is particularly expensive.